misc/ssh_tg_notify: Check that PAM_RHOST is defined

roles/misc/ssh_tg_notify/templates/notify.sh

@@ -12,7 +12,7 @@ sendMessage() {
     curl -s --max-time "$TIMEOUT" -H "Content-Type: application/x-www-form-urlencoded" -d "chat_id=$1" -d "disable_web_page_preview=1" -d "parse_mode=Markdown" -d "text=$2" "$URL" >/dev/null
 }
 
-if [[ "$PAM_SERVICE" == "sshd" && "$PAM_TYPE" == "open_session" && "$PAM_USER" != "git" && -z "$TMUX" ]]; then
+if [[ "$PAM_SERVICE" == "sshd" && "$PAM_TYPE" == "open_session" && "$PAM_USER" != "git" && -z "$TMUX" && -n "$PAM_RHOST" ]]; then
     IP="$PAM_RHOST"
     cache_file="${CACHE_DIR}/${IP}-${PAM_USER}"
     cache_mtime=$(stat --format="%Y" "$cache_file" 2>/dev/null)